HasDescendantInvalidationAllSubjects.html

<!DOCTYPE html>
<html>
<head>
<script src="../resources/runner.js"></script>
<style>
  div { color: grey }
  .a:has(.b) { color: green }
</style>
</head>
<body>
<div id=container class=a></div>
<script>

function makeTree(depth) {
  var parent = container;
  for (var i = 0; i < depth; i++) {
      var child = document.createElement("div");
      child.classList.add("a");
      child.id = "child" + i;
      parent.appendChild(child);
      parent = child;
  }
}

makeTree(100);
container.offsetHeight; // force recalc style

var runFunction = function()
{
  child0.classList.toggle("b");
  container.offsetHeight; // force recalc style
  child0.classList.toggle("b");
  container.offsetHeight; // force recalc style

  child99.classList.toggle("b");
  container.offsetHeight; // force recalc style
  child99.classList.toggle("b");
  container.offsetHeight; // force recalc style
}

PerfTestRunner.measureRunsPerSecond({
  description: "Measures performance of the '.a:has(.b)' invalidation with multiple subject elements in extream case.",
  run: runFunction
});

</script>
</body>
</html>

chromium/third_party/blink/perf_tests/css/HasDescendantInvalidationAllSubjects.html